Some apparatuses having a printing function are equipped with a sheet winding mechanism which winds a sheet in a roll shape. For example, in many cases, a merchandise information processing apparatus (for example, a point of sales (POS) terminal) is equipped with a sheet winding mechanism which winds a journal having transaction information printed thereon in a roll shape. The sheet winding mechanism includes a detachable winding core, and winds a sheet around the winding core.
In order to maintain winding performance at a high level and also to enable the user to readily attach or detach a winding core, many sheet winding mechanisms and winding cores are made complicated in configuration. An apparatus complicated in configuration tends to be high in cost. As the cost of an apparatus used for winding (for example, a sheet winding mechanism or a winding core) becomes higher, the cost of the entire printer also becomes higher.